Page 87 - Commercial Underwriting Mandates & Guidelines Binder Addendum

Annexure H: Ammonium Nitrate Fact Sheet
FACT SHEET
AMMONIUM NITRATE SAFETY CONTINUED
Requirements for safely storing ammonium nitrate can be found in NFPA® 400, Hazardous Materials Code. At a minimum, measures should be established to ensure the quantities are:
• Stored away from substances that can cause ammonium nitrate to destabilize
• Stored in facilities located a safe distance from other struc- tures and people
Chapter 11 of NFPA 400 provides additional safeguards for storage quantities exceeding 1,000 lb (454 kg) and covers specific issues regarding new and existing construction, such as the following:
• New Construction:
° Needs to be noncombustible, without exception
° The use of wooden or other combustible bins for the storage of ammonium nitrate — which was previously allowed if the bins were protected against impregnation by ammonium nitrate — is prohibited
° Ammonium nitrate storage buildings of any construction type with combustible contents must be sprinklered
° Floor sloping and drainage is required to provide further protection against the confinement of molten or spilled ammonium nitrate
• New Construction and Existing Facilities:
° Must comply with all the construction requirements that
were in place when the facility was built
° Sprinklers are required retroactively for facilities that are of combustible construction or that have combustible contents
° Water-based suppression systems are the only type allowed in areas containing ammonium nitrate, as the pur- pose of the water is both to suppress an exposure fire and to cool the ammonium nitrate. The water helps to prevent both decomposition of ammonium nitrate and the forma- tion of molten ammonium nitrate, which, when confined, can create an explosion hazard.
Detection and Notification Systems
In both new and existing facilities that store ammonium nitrate, a fire alarm system with fire detection is required throughout under NFPA 400, along with an approved public notification/ siren system. Oxidizers such as ammonium nitrate can cause the growth phase of a fire to accelerate rapidly compared to fires involving ordinary combustibles. Given this heightened urgency, building occupants should be notified of the need to evacuate the building faster than they would during an ordinary combustible fire. Individuals in the surrounding area need to be notified too.
Emergency Response Issues
NFPA 400 also includes suggestions for firefighting procedures and considerations in determining when to fight fires involv- ing ammonium nitrate and when to evacuate. The document provides references, types of ammonium nitrate, and the conditions that can cause explosions. In addition, NFPA 400 includes a table that shows typical ammonium nitrate products and their composition and additional resources for information on the safe handling and storage of ammonium nitrate (see Annex E).
Learn More
Get free access to the 2019 edition of the code: NFPA 400, Hazardous Materials Code.
Access the latest coverage in the NFPA Journal® on the 2020 explosion in Beirut, Lebanon, including a recent podcast and article.
Learn about ammonium nitrate regulatory gaps on NFPA XchangeTM.
Read the 2017 report, “Variables Associated with the Classification of Ammonium Nitrate — A Literature Review,” from the Fire Protection Research Foundation.
This material contains some basic information about NFPA® 400, Hazardous Materials Code. It identifies some of the requirements in this document as of the date of publication. This material is not the official position of any NFPA Technical Committee on any referenced topic which is represented solely by the NFPA documents on such topic in their entirety. For free access to the complete and most current version of all NFPA documents, please go to nfpa.org/docinfo. While every effort has been made to achieve a work of high quality, neither the NFPA nor the contributors to this material guarantee the accuracy or completeness of or assume any liability in connection with this information. Neither the NFPA nor the contributors shall be liable for any personal injury, property, or other damages of any nature whatsoever, whether special, indirect, consequential, or compensatory, directly or indirectly resulting from the publication, use of, or reliance upon this material. Neither the NFPA nor the contributors are attempting to render engineering or other professional services. If such services are required, the assistance of a professional should be sought.
© 2020 National Fire Protection Association / September 2020
Commercial Underwriting Mandates & Guidelines Addendum – Binder – Version 4 2022 2